1  /* { dg-do run } */
       2  /* { dg-options -w } */
       3  
       4  /* count() used to give 1 owing to a buggy test for varargs.  */
       5  #define count(y...)  count1 ( , ##y)
       6  #define count1(y...) count2 (y,1,0)
       7  #define count2(_,x0,n,y...) n
       8  #if count() != 0 || count(A) != 1
       9  #error Incorrect vararg argument counts
      10  #endif
      11  
      12  /* Test for changed behavior of the GNU varargs extension.
      13     ##args, where args is a rest argument which received zero tokens,
      14     used to delete the previous sequence of nonwhitespace characters.
      15     Now it deletes the previous token.  */
      16  
      17  #include <string.h>
      18  
      19  #define S(str, args...) "  " str "\n", ##args
      20  
      21  int
      22  main()
      23  {
      24    const char *s = S("foo");
      25    return strchr (s, '\n') == NULL;
      26  }